1. Field of Invention
This invention relates to orthopedic wrist braces, more particularly, to a novel brace affixed around the distal radioulnar joint (“DRUJ”) that can be donned and doffed unilaterally, when worn does not compress or irritate the ulnar styloid and does not restrict wrist motion, and is significantly simpler, more effective, and less costly to manufacture than other types of wrist braces.
2. Description of the Related Art
A wide variety of wrist support devices are known in the art. The term “brace” as used herein means an orthopedic support device that does not contain a rigid or semi-rigid structural element. The term “splint” as used herein means an orthopedic support device that does contain a rigid or semi-rigid structural element to immobilize or partially immobilize a musculoskeletal region, typically a joint. The term “wrist” herein means the wrist of a person to which a wrist support device is affixed. The term “DRUJ area” means a band around the arm from the radiocarpal joint to a line approximately 15 mm proximal of the ulnar styloid. Severe pain can be associated with injury of the distal radioulnar joint.
A proximal row of bones in the wrist (i.e., scaphoid, lunate, triquetrum, and pisiform) articulate with the distal ends of the radius and ulna in a constrained space to allow three degrees of freedom at the wrist. Relative to the forearm, these hand movements include flexion-extension, pronation-supination, and radial/ulnar deviation. Relative stability of such mobility requires a coordinated system of ligaments, muscles, and tendons. The ulna represents the non-rotating, stable and weight-bearing part of the forearm around which the radius rotates in pronation and supination. The distal end of the radius together with the hand and what is held in the hand rest against the stable, immobile ulnar head, which acts as the keystone of the wrist. Mobility and stability of the distal radioulnar joint is accomplished by the combined action between fully congruent articulating surfaces and intact radioulnar ligaments. Following a distal radius fracture or other nearby trauma, the ulnar notch of the distal radius will frequently no longer be congruent to the ulnar head due to the displacement of the radius into dorsal angulation, radial angulation, or both angulations. In such an injury, stabilizing DRUJ ligaments often tear. Hagert, C. G, Handchir. Mikrochir. Plast. Chir. January 1994:26(1):22-26.
The triangular fibrocartilage complex (“TFCC”) comprises the ligamentous and cartilaginous structures that suspend the distal radius and ulnar carpus from the distal ulna. The TFCC is the major ligamentous stabilizer of the DRUJ and the ulnar carpus. Humankind is differentiated from lower primates by a radiocarpal joint with a TFCC interposed between the ulna and carpus. The TFCC improves wrist functional stability and allows the above-mentioned three degrees of freedom at the wrist: flexion/extension, supination/pronation, and radial/ulnar deviation. Injuries to the DRUJ, especially to the TFCC, present with ulnar-sided wrist pain, frequently with “clicking” or “clunking”.
The causes of wrist pain can be divided into three categories: mechanical, neurologic, and systemic. Psychosocial factors can also have a profound influence on wrist pain, particularly when the patient may be eligible for workers' compensation, so reduction of “wrist pain”, which may in fact be localized to the DRUJ, is of great economic consequence. To prevent, or to ameliorate, post-traumatic, “wrist pain”, a wrist brace or wrist splint is typically prescribed or adopted sua sponte, especially in connection with corrective osteotomy of the radius at a fracture site.
Correct compression of the distal radioulnar joint, or DRUJ, improves congruity between the ulnar notch of the radius and the head of the ulna, thereby providing prophylaxis for a subject at risk for DRUJ injury (or re-injury) and therapy for a subject during rehabilitation after surgery or a DRUJ or TFCC injury. Correct compression of the DRUJ reduces “wrist pain”, especially for load-bearing tasks, when the injury is in the DRUJ or TFCC. Incorrect compression can exacerbate the injury.
User-applied orthopedic support devices are generally differentiated by (1) sleeve (aka pull-on), versus wrap, structure, (2) brace versus splint structure, (3) adjustability of the device, (4) limitations on joint motion when wearing the device, and (5) fastening means (e.g., D-ring, reclosable fasteners, straps and slits, lacing, clasps, snaps, buttons, hooks, rivets, and buckles). “Mating-halves” reclosable fasteners include hook and loop fasteners, e.g., Velcro® fasteners (Velcro Industries, Brampton, ON), and mushroom head fasteners, e.g., 3M® Dual Lock fasteners (3M, St. Paul, Minn.).
There are apparently no braces or splints designed specifically for the DRUJ. As of the application date, a search string of “distal radioulnar joint brace” and “distal radioulnar joint splint” returned no hits in major Internet search engines, and no U.S. patents or published applications contained in the title the term “distal radioulnar joint” and concern braces or splints. There are hundreds of designs for “wrist braces” and “wrist splints”, but typically the structure of wrist braces and wrist splints covers at least the forearm, DRUJ, radiocarpal joint, metacarpals, and surround the base of the thumb; some braces and splints also cover the metacarpophalangeal joint and/or the elbow. The prophylactic and therapeutic objects of wrist braces and wrist splints are stabilization and immobilization, respectively, of the radiocarpal, metacarpal, and even metacarpophalangeal areas as distinct from the DRUJ, and DRUJ/TFCC. Currently available wrist braces and wrist splints (including specialized devices, such as ulnar deviation splints, wrist braces with metacarpophalangeal (“MCP”) support, dorsal wrist cockups, wrist orthoses, pressure splints, wrist hinges, wrist wraps, and spica splints) can do more harm than good if only a DRUJ injury is involved, especially if full wrist motion is desired. In particular, “wrist wrap” type wrist braces, as a result of the elastic materials used in their construction, provide inadequate support for pronation and supination, and cannot be adjusted for load-bearing tasks. The ulnar styloid has no physical padding, is highly innervated, and is inherently vulnerable to bruising, irritation. and laceration. The deficiency of current wrist braces and wrist splints when used for DRUJ/TFCC support arises from undesirable abrasion and irritation of the ulnar styloid, compression of the radial and ulnar arteries, excessive compression of the proximal portion of the DRUJ (i.e., that part proximal to the ulnar styloid), inadequate compression of the distal portion of the DRUJ (i.e., that part distal to the ulnar styloid), complexity of fastening means preventing unilateral donning and doffing, and cost of manufacturing.
Patients who present with injuries to the TFCC describe severe pain and dysfunction to their wrists that surgeons are hesitant to treat surgically. Conservative treatment includes cortisone injections, and splinting of the elbow into 90 degrees of flexion and immobilizing the wrist in neutral. These treatments have substantially poor outcomes and dramatically high risk factors, including contractures of the elbow and wrist. In addition, these treatments are significantly disabling. When these patients present, they typically find that a circumferential squeezing of the DRUJ area can eliminate their “wrist pain” (in fact, they have DRUJ or DRUJ/TFCC pain). Many patients independently look for wrist wraps in the market place to recapture the effect of the pain-relieving squeeze. Wrist wraps, however, do not replicate the compressive force of the patient's opposite hand or a therapist's hands, especially in the area proximal to the radiocarpal joint.
The manufacturers of wrist braces and splints have arguably not properly characterized the problem of “wrist pain” by segmenting the problem into devices to treat pain distal to the radiocarpal joint and devices to treat pain proximal to the radiocarpal joint. The present invention expressly addresses the segment of “wrist pain” proximal to the radiocarpal joint (aka “ulnar-sided wrist pain”), i.e., pain associated with injury to the DRUJ or DRUJ/TFCC. The technical problem to be solved is to provide a DRUJ and TFCC support device that does not irritate or compress the ulnar styloid, provides adjustable compression of the proximal portion of the DRUJ that is independent of adjustable compression of the distal portion of the DRUJ, provides adequate support through pronation and supination, provides adjustment for load-bearing tasks, provides equal benefit on either the dextral or sinistral DRUJ area, and provides unilateral (using one hand) donning and doffing. It would be further desirable for the solution to this problem to avoid the use of fasteners that are difficult to use, that irritate the DRUJ area, and that add cost to manufacturing. It would be further desirable for the solution to this problem to be washable and durable, and to accommodate a range of DRUJ area circumferences, bilateral use, types of user activity (e.g., sports, office work, construction work), and price points.